1. Field of the Invention
The present invention relates to a radiating device for radiating heat of an electronic component such as a semiconductor integrated circuit package to the atmosphere.
2. Description of the Background Art
Recently, higher responsiveness and higher integration of integrated circuits used for electronic devices such as computers have been in greater demand. Accordingly, density of power consumption of an integrated circuit has been increased, and the operating temperature of the electronic component has been increased. In order to cool the electronic component, a radiating device such as a heat sink has been used.
FIG. 11 shows a conventional radiating device 2 placed on a semiconductor integrated circuit package 1. Radiating device 2 includes a thin rectangular base plate 3 which is in surface-contact with the top surface of semiconductor integrated circuit package 1, and a number of pins 4 erected on the top surface of base plate 3 so as to increase the surface area of the radiating device. Typically, radiating device 2 is formed of aluminum. The heat of semiconductor integrated circuit package 1 is transmitted to radiating device 2, and is radiated to the atmosphere from the surface of radiating device 2.
FIG. 12 shows a conventional fin type radiating device 5. Radiating device 5 includes a circular base plate 6 which is in surface-contact with the top surface of the semiconductor integrated circuit package, and a plurality of fins 7 erected on the top surface of base plate 6 so as to increase the surface area of the radiating device. Typically, radiating device 5 of this type is also formed of aluminum.
In the conventional radiating device such as shown in FIGS. 11 and 12, radiating effect is improved by increasing the surface area. However, such conventional radiating devices not provide satisfactory cooling results when used with the most modern electronic components, the higher responsiveness and higher integration of which have been much desired.
A heat pipe has been known as another example of a radiating device for cooling an electronic component. A heat pipe is obtained by reducing the inner pressure of an air tight container formed by closing both ends of a pipe, and by sealing into the pipe a little heat carrier such as water or alcohol, which is called a working fluid. At a heated portion of the heat pipe, the fluid turns into steam or gas, the gas radiates or loses heat when it moves away from the heated portion, and turns into liquid. The liquid returns to the heated portion because of capillary, for example action. The heat is transmitted from the heated portion to the radiating portion by the repetition of this phenomenon.
A heat pipe is placed on the top surface of an electronic component in order to cool the electronic component such as a semiconductor integrated circuit package. Since the heat pipe is linearly in contact with the electronic component, it is inferior in efficiency of heat transmission from the electronic component to the heat pipe.